Abstract/Summary

arge M3 tides on the broad-continental shelf between Itajai and Santos, Brazil, are interpreted as a damped ‘organ-pipe’ quarter-wave resonance between the coast and the shelf edge. This view is supported by a simple semi-analytic model of the shelf as a shallow broad gulf adjacent to an infinite ocean. The model is used to explore the nature of the two simplest forms of shelf motion which may be strongly excited by the ocean over a range of shelf parameters.